Methine dyestuff intermediates



METHINE DYESTUFF INTERIVIEDIATES Nicholas J. Kartinos, Nazareth, Pa., assignor to General Aniline & Film Corporation, New York, N. Y., a corporation of Delaware No Drawing. Application October 9, 1953, Serial No. 385,267

1 Claim. (Cl. 260-3474) This invention relates to methine dye intermediates and particularly to a new class of tetrahydrofurfuryl esters which are employed as intermediates in the preparation of vivid or fluorescent methine dyes for coloring lacquers, resins, printing inks and for dyeing acetate rayon, polyesters, and other fibers.

It is known that methine dyes prepared by the condensation of aromatic p-aminoaldehydes, such as, for example, p-diethylaminobenzaldehydes, p N butyl N isobutylaminobenzaldehydes, p-(N-phenyl-N-methyl)-aminobenzaldehyde and the like, with an active methylene compound, such as, cyanoacetic acid, esters or amides thereof, malonic acid, malonitrile, malonic esters, have been proposed for the dyeing of cellulose acetate and other synthetic fibers from their aqueous suspensions or solutions. Despite the fact that all of these dyes dye cellulose acetate and other synthetic fibers, the shades obtained, however, are essentially non-fluorescent and the fastness to light and washing is only fair.

I have found that by using tetrahydrofurfuryl esters of cyanoacetic or malonic acid as the active methylene compounds in the aforesaid condensation reaction, one can obtain dyestuffs which dye cellulose acetate and other synthetic textile fibers with very bright, fluorescent yellow to red-orange shades of excellent fastness to light. In addition to this property, the dyestuffs possess unusual wash fastness. The tint is bathochromic when compared to the analogous dyestuffs from the aromatic p-aminoaldehydes and the foregoing active methylene compounds. Moreover, the dyes when employed as fluorescent substances yield a fluorescent yellow to orange color which is redder, brighter and stronger than any of the heretofore employed methine dyes of similar fluorescent range.

Accordingly, it is the principal object of the present invention to provide a new class of tetrahydrofurfuryl esters which are of value as intermediates for the preparation of methine dyes of fluorescent substances. These esters are characterized by the following general formula:

wherein R represents a halogen such as bromine and chlorine, cyano and carbalkoxy. The alkyl portion of the carbalkoxy is lower alkyl of l to 5 carbon atoms, such as, methyl, ethyl, butyl, isobutyl, propyl, isopropyl and amyl which may be substituted by a chloro, cyano, hydroxy, or tetrahydrofuryl group.

The esters characterized by the foregoing general formula are readily and conveniently prepared by condensing a negatively substituted acetic acid, cyanoacetic acid, a potential cyanoacetic acid (e. g. haloacetic acid), malonic acid or its half ester with tetrahydrofurfuryl alco- 1101 in the presence of an acid catalyst, such as, for example, hydrochloric acid, hydrogen chloride, sulfuric acid, phospholeum, and phenyl and alkane sulfonic acids.

The negatively substituted acetic acids employed, are

nited States Patent 0 for example, a-monohaloacetic acid, e. g. chloroacetic acid, bromoacetic acid, iodoacetic acid, cyanoacetic acid, a-carboxyacetic acid, e. g. malonic acid, a-carbalkoxyacetic acid, monomethyl malonate, monoethyl malonate, monopropyl malonate, monobutyl malonate and the like; u-carb(substituted alkoxy)acetic acid, monohydroxymethyl malonic, monohydroxyethyl malonic, monohydroxypropyl malonate, monohydroxybutyl malonate, etc.

2 moles (170 grams) of cyanoacetic acid, 2.2 moles (222 grams) of tetrahydrofurfuryl alcohol, 300 chloroform, and 10 grams of mixed lower alkane sulfonic acids were added to a reaction flask and equipped with a water separator and a condenser; the mixture was heated under reflux until no more Water separated. After cooling, the reaction mixture was washed with dilute sodium hydroxide solution until all of the acids were neutralized and extracted. The organic layer was separated, dried and the chloroform removed by distillation. The residue was distilled under reduced pressure, to yield 196.5 grams of a colorless product having a boiling point of -44 C. at 0.5 mm, which corresponds to 59% of the theoretical amount.

Example 2 H CCH Example 3 Ego-m2 u 11 H2 OHCHgO-CCHzC-OC7H5 Example 1 was repeated with the exception that 2 moles of cyanoacetic acid were replaced by 2 moles (264 grams) of monoethyl malonate.

Example 4 HZO CH $1) H2 CHCH OOCH OI Example 1 was repeated with the exception that 2 moles of cyanoacetic acid were replaced by 2 moles (189 grams) of monochloroacetic acid.

Example 5 group exhibits a bathochromic shift as compared to an ii I ethdll gdoup' 1 (D P d k) fib h g t n acron p0 yester u out tra emar er,t e H2O CHCH2 O C CHT CTO C2HGN compound is a brilliant and fluorescent red-yellow dye.

0 5 It has good light fastness and excellent wash fastness. Example 1 was again repeated with the exception that 2 Examp 1e 9 moles of cyanoacetic acid were replaced by 2 moles (314 grams) of monocyanoethylmalonate.

The following examples illustrate the utilization of C CH=C the foregoing esters in the preparation of dyestufis, inl-ts, 1O CHQCHZCOZCBZCQ \COZCHTOH OH2 etc. having new and superior properties.

Example 6 About 12.5 grams of N-ethyl-fi-(4-formylphenyl)- OrHs ON aminoethyl propionate, 8.5 grams of tetrahydrofurfuryl H: n cyanoacetate, 25 ml. of 2-propanol, and 5 drops of G 0 "& b'd dhtdf 10 piper-i me were com me an eae or minutes CH5 OOZCHQTCQ under reflux. Ayellow solid separated on cooling. There 0 was obtained 17 grams of dyestuff having a M. P. of About 16.9 grams of tetrahydrofurfuryl cyanoacetate, 7375 C. (85% of theory). 17.7 grams of 4-diethylarninobenzaldehyde, 50 ml. of 2- 20 The resultmg COHIPOUIKI is an excellent green-yellow propanol nd 5 drops f i idi were cgmbined d dye for acetate rayon. It exhibits unusual tinctorial heated under reflux for 1 hour. Upon cooling and scratch- Strength and Wash fastness when compal'ed i116 methine i'ng a fluorescent, bright yellow solid was induced to crysderived flOm the abQVB aldehyde and ethyl cyafloacetatea tallize. There was obtained 15 grams of dyestutf having E l 10 a M. P. of 64-65 c. (46% of theory). 9

This compound dyes acetate silk in a brilliant green- C112CH:4 yellow shade. As a dye it exhibits excellent light fastorr gn C ness and tinctorial strength and considerably improved 00 CH CH CH wash fastness when compared to the methme compound 2 2- a derived from ethyl cyanoacetate and p-diethylaminobenz- 0 aldehyde. About 16 grams of fi,5-{4-formyl phenyl)-i1nino bis- Example 7 ethyl propionate in 30 ml. of chloroform, 8.5 grams of CHgO CHa-CH: NC 1 CN OH2CH2 O o=ou CH=O CH2 CHCH303O COzCHz-CH CH9 CH3 O 0 About 3.88 grams of 2,5-dimethoxyterephthaldehyde, 4O tetrahydrofurfuryl cyanoacetate, and5 drops of piperidine 6.76 grams of tetrahydrofurfuryl cyanoacetate, ml. were combined and heated for 5 minutes under reflux. of ethanol, and 2 drops of piperidine were combined and The chloroform was removed and the viscous residue crysheated several minutes. A brilliant red-orange solid tallized from 100 ml. of ethanol. There was obtained separated immediately. The solid was collected. There 20.5 grams of a bright yellow solid having a M. P. of was obtained 8 grams of dyestuff having a M. P. of 40- 5 9092 C. (87% of theory). 46 C. (81% of theory). This methine dye exhibits good affinity for cellulose This compound when appropriately mixed with bodied acetate with excellent light and wash fastness and vivid linseed oil results in a lithographic ink. A lithographic green-yellow shade. print from this ink is brilliant, fluorescent red-orange in Emmple 11 color. It is brighter, redder, and stronger than the litho- 5Q graphic print that results when the dye derived from the ON CH -C H, above dialdehyde and ethyl cyanoacetate is employed. (011301120O2GHZCH2)5N-OCH=C/ When appropriately formulated with a resin (e. g. Beetle resin), and coated on paper, this compound results 01 OOZCHTOE in a brilliant, fluorescent orange resin coating. 0

Example 8 About 17.3 grams of {3,[Y-(3-chloro-4-formyl phenyl)- CHz-CH; NC CN CH2-CH1 C=HCQN OH=C l CH1 CH-CHzOzC COgCHz-CH CH9 CH3 O 0 About 12 grams of N-methyl imino-p,p-dibenzaldeimino bis-ethyl propionate in 30 ml. of chloroform, 8.5 hyde, 17 grams of tetrahydrofurfuryl cyanoacetate, 50 ml. grams of tetrahydrofurfuryl cyanoacetate, and 5 drops of of 2-propanol, and 5 drops of piperidine were combined piperidine were combined and heated under reflux for 30 and heated under reflux for 30 minutes. The product minutes. The chloroform was distilled off. The resulting crystallized on cooling. There was obtained 27.5 grams oil resisted crystallization. of a fluorescent orange solid having a M. P. of NZ-108 This methine compound dyes cellulose acetate in a vivid C. (100% of theory). green-yellow shade with excellent wash and light fastness.

This bis-methine compound when applied to acetate E I 12 rayon is brilliant yellow dye with excellent light and wash xamp fastness and exceptional tinctorial strength. When com- 0N Hz Ha pared to the bis-methine derived from N-methyl iminocmgmg p,p-dibenzaldehyde and'ethyl cyanoacetate, the dyestuff p CO CH of this example displayed enhanced tinctorial strength. CH3 2 2 It is also redder in shade. Thus, the tetrahydrofurfuryl 0 About 16 grams of fl,;8'-(3-methyl-4-formyl phenyl)- imino bis-ethyl propionate in 30 ml. of chloroform, 8.5 grams of tetrahydrofurfuryl cyanoacetate, and 5 drops of piperidine were combined and heated under reflux for 30 minutes. The chloroform was distilled ofi resulting in a heavy viscous oil.

The liquid methine compound dyes cellulose acetate a vivid green-yellow shade with excellent aflinity, wash and light fastness.

Example 13 CHrCHg COzCHgCH 6 lected and dried. There was obtained 15.5 grams of dyestufi having a M. P. of 6164 C. of theory).

This methine compound dyes cellulose acetate a vivid green-yellow color with excellent wash and light fastness and excellent aflinity.

I claim: Methine dye intermediate having the following formula:

H,G0H, o H: 41HCHr-O --CH:CN

References Cited in the file of this patent UNITED STATES PATENTS 1,989,701 Lawson Feb. 5, 1935 2,234,615 Alexander Mar. 11, 1941 2,410,197 Borglin Oct. 29, 1946 OTHER REFERENCES Eddy et al.: J. Econ. Entomol. 41, p. 33 (1948). 

